Thompson got the call for the Gamecocks (10-2) because starter Connor Shaw sprained his left foot last week against Wofford. And the Gamecocks sophomore made the most of it with TD passes of 13 and 6 yards to Bruce Ellington and 34 yards to Ace Sanders.

The Tigers (10-2) were grounded by Clowney, the Gamecocks star defensive end who set his school's single season-record with 13 sacks.

South Carolina coach Steve Spurrier won his 65th game in eight seasons, surpassing Rex Enright for most victories by a South Carolina coach. The Gamecocks finished with 10 victories for a second consecutive season, a first in program history.

"When we play Clemson, they don't seem to play very well," Spurrier said.

That was true again in this one as Clemson's offense and quarterback Tajh Boyd never got on track. The Tigers came leading the Atlantic Coast Conference and were sixth in the country with 535 yards a game. They finished with 328 yards in this one, 165 over the final three quarters.

Boyd was 11 of 24 for 183 yards and two crushing interceptions, the last one that set up Thompson's clinching TD throw to Ellington with 4:17 left.

When it was over, South Carolina's players started their fans in the chant, "Four In A Row! Four In A Row!"

It's been 58 years since the Gamecocks could say that, their one-and-only four-game series win streak occurring from 1951-54.

South Carolina's win made the Southeastern Conference 4-0 against ACC opponents Saturday.

Thompson found out Wednesday he'd get his second start of the season because of Shaw's injury. "For a guy who hadn't played much, he did very well," Spurrier said.

Spurrier said Shaw should be ready for South Carolina's bowl. Did Thompson think he'd earned another start? "I'm not worried about that. We just beat Clemson four times in a row," he said.

Clemson coach Dabo Swinney said his team was unable to get the ball in the second half, running just 19 plays to South Carolina's 51.

"We just couldn't stop them on third down. The third quarter was huge. We had too many penalties, too many turnovers and South Carolina did a great job of controlling the ball," said Swinney, now 1-4 against the Gamecocks.

Clemson's oldest players came into their senior day ceremonies hoping to avoid an oh-fer against their rivals. The Tigers looked like they got a break before the game when Spurrier said Thompson would start for Shaw, who riddled Clemson for 317 yards in last season's 34-13 victory.

Shaw sprained his left foot in the win over Wofford last week and barely practiced during the week. Shaw came out in full uniform and helmet during warmups and appeared to move easily. Still, this was Thompson's start and he kept the Gamecocks in it.

Thompson answered Clemson's 16-play, 85-yard touchdown drive with a solid showing of his own on South Carolina's following series. He went 4-for-4 for 56 yards, including a 13-yard TD pass to Bruce Ellington.

Boyd showed Clemson's quick strike capabilities moments later, hitting DeAndre Hopkins for a go-ahead, 43-yard touchdown pass. It was Hopkins' ninth straight game with a touchdown catch and extended his school record to 16 scoring grabs this season.

Clemson faced its stoutest defensive test since a 49-37 loss at Florida State. The Gamecocks defense ranks 13th nationally and is unaccustomed to allowing huge chunks of yardage or scads of points.

The shootout quickly turned into a slugfest after Boyd's two first-quarter scores, Clemson managing just 74 yards in the second quarter. Not that South Carolina, with Thompson under center, could get much going, either.

Thompson drove the Gamecocks to the Tigers' 9 but had to settle for Adam Yates' 27-yard field goal that cut the lead to 14-10.

Clowney had 1.5 sacks in the opening half, and then added three more in the final two quarters to best the team's single-season mark of 10 shared by Andrew Provence (1982) and Melvin Ingram (2011).

It was the Gamecocks' defense that shook up Clemson's usually fast-paced attack. Boyd was pressured much of the period and was just 8 of 17 for 131 yards and an interception while trying to score before the half.

Boyd was hit on the throw, the ball floating into the middle of the field and DeVonte Holloman diving backward for the grab. It was Holloman's third career interception in four games against Clemson.